A new, deadly H5N8 strain of avian influenza penetrated the biosecurity defenses of a National Institute of Animal Science (NIAS) campus, prompting authorities to cull all of the facility’s 11,000 hens and 5000 ducks.

The devastating loss could set back poultry experiments at the NIAS lab for 2 years. “It will likely to take up to 95 weeks to fully rebuild [the flocks] and resume normal research,” says Kim Sung-Il, head of the contingency team at the Rural Development Administration, which oversees NIAS. Kim adds that the institute, which studies breed improvement and animal husbandry techniques, will reconstitute its flocks from birds kept at other facilities.

A wild goose that died of the virus was found 10 kilometers from NIAS’s Suwon campus, near Seoul, on 1 February. The entire NIAS staff went to work disinfecting and shoeing away wild birds at the three centers that keep poultry. Despite those efforts, 30 ducks were found dead on 2 March at the Cheonan campus, 85 kilometers south of Seoul. The next day, authorities confirmed the cause of death as H5N8 avian influenza. NIAS immediately initiated culling, which was completed on 4 March.

The incident highlights the difficulty of protecting poultry farms from circulating avian influenza viruses. “We are taking this situation very seriously,” said Lee Jun-Won, deputy agriculture minister, at a press conference yesterday in Seoul. He noted that NIAS has the country’s most secure facilities and most vigilant staff. Lee said they were looking at three possible routes the virus could have taken onto campus: wild birds, NIAS vehicles, and supply deliveries. “We will determine the reason for the infection, and we are going to hold those responsible accountable,” he said.

The culprit H5N8 strain had never before been seen in such a deadly form when it surfaced on farms in central South Korea on 17 January. Despite control efforts that have included culling millions of chickens and ducks, the virus has spread virtually nationwide and outbreaks are still being reported. It has also killed hundreds of Baikal teal and other migratory birds. There have been no reports of human infections.

*Clarification, 6 March, 8:25 a.m.: The text was revised to clarify that the H5N8 outbreak occurred on the Cheonan campus.